Cameron Advances in Surgery 2013

1. Auflage 2014
ISBN: 978-1-4557-7296-4
Verlag: Elsevier HealthScience EN
Format: EPUB
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)

E-Book, Englisch, Band Volume 2013, 100 Seiten

Reihe: Advances

Each year, Elsevier's Advances in Surgery reviews the latest techniques, data, and evidence in general surgery. A distinguished editorial board, led by Dr. John L. Cameron of Johns Hopkins, identifies current areas of major progress and controversy, and invites specialists from around the world to contribute comprehensive, detailed reviews on these topics.

Autoren/Hrsg.

Cameron, John L.

Leseproben

Repair of Giant Ventral Hernias
Jai Bikhchandani, MD* and Robert Joseph Fitzgibbons, Jr., MD,     Department of General Surgery, Creighton University Medical Center, 601 N 30th Street, Omaha, NE 68131, USA. E-mail address: [e-mail] *Corresponding author. Keywords Giant ventral hernia Incisional hernia Component separation Loss of domain Key points
• Repair of huge ventral hernias is technically challenging for the surgeon and a major operation for the patient and should be performed by experienced surgeons in centers that are used to caring for patients who are commonly massively obese, with significant comorbidities. • Preoperative medical optimization of patients is an important part in the overall management of these large hernias. • Conventional component separation with retromuscular mesh repair is the workhorse operation, which successfully deals with many giant ventral hernias, but multiple alternative strategies must be available to address situations in which myofascial elements are completely deficient or there is significant loss of domain. • The complexity of this surgery is reflected by recurrence rates ranging from 10% to 30% and wound complication rates as high as 40% to 50% in experienced centers. Introduction
Approximately 1 million abdominal wall hernia repairs are performed in the United States each year [1]. Of these operations, roughly 69% are groin, 15% umbilical, 9% incisional, and 7% are miscellaneous, (eg, Spigelian, lumbar, traumatic). The term ventral is most commonly used to describe collectively those hernias that occur outside the groin and is the convention that is used in this article. It is estimated that about 5% of the population develop a ventral hernia at some time in their life. Most hernias are small and can be managed in general practice using standard techniques. However, there is a subset of these patients who develop enormous hernia sacs. These hernias are usually described as giant ventral hernias. Other synonyms used in the literature for giant ventral hernia are large, massive, huge, or complex ventral hernia. Sometimes, the whole visceral contents herniate into the hernia sac outside the abdominal cavity (Fig. 1). These hernias are usually associated with loss of domain, because the abdominal cavity proper shrinks with the visceral contents lying chronically outside it. If an attempt is made to force these extra-abdominal viscera into the native abdominal cavity, there can be severe respiratory and cardiovascular compromise, causing the abdominal compartment syndrome.
Fig. 1 (A, B) Computed tomography scan (axial and sagittal view) of a patient with giant ventral hernia. Note that a significant amount of the intra-abdominal viscera including the stomach is in the hernia. Repair of huge ventral hernias with significant loss of domain is technically challenging, with high mortality, morbidity, and recurrences rates [2,3]. Moreover, these hernias are often associated with overlying skin ulceration, persistent infection, enterocutaneous fistulas, diverting stomas, and morbid obesity. Many of these hernias have been repaired multiple times, and each repair has failed, distorting the anatomy of the abdominal wall further. This article focuses on the management of these complex huge ventral hernias and the newer advances in abdominal wall reconstructions. Surgical anatomy
The root cause of a ventral hernia is failure of key anatomic elements to contain intra-abdominal viscera within the abdominal cavity. Repair of ventral hernias requires a thorough understanding of the anatomy of the abdominal wall [4]. The abdominal wall is made up of the centrally located rectus abdominis muscles and the 3 lateral muscles: the external oblique, internal oblique, and transversus abdominis. The linea alba is the midline confluence of the aponeuroses of these muscles. The external abdominal oblique muscle (Fig. 2) is the most superficial of the 3 lateral abdominal muscles. The external abdominal oblique arises from the posterior aspects of the lower 8 ribs and interdigitates with both the serratus anterior and the latissimus dorsi at its origin. The direction of the muscle fibers varies from nearly horizontal in its upper portion to oblique in the middle and lower portions. The horizontal fibers, which originate posteriorly, insert onto the anterior portion of the iliac crest. The obliquely arranged anteroinferior fibers of insertion fold on to themselves to form the inguinal ligament. The remaining portion of the aponeurosis inserts into the linea alba after contributing to the anterior portion of the rectus abdominis sheath. The middle layer of the lateral abdominal group is the internal abdominal oblique muscle (see Fig. 2). This muscle primarily arises from the iliac fascia along the iliac crest and forms a band of iliac fascia fused with the inguinal ligament. The uppermost fibers course obliquely toward the distal ends of the lower 3 or 4 (floating) ribs. The muscle fibers of the internal oblique fan out, following the shape of the iliac crest, so that the lowermost fibers are directed inferiorly. The aponeurosis of the internal oblique (Fig. 3A) above the level of the umbilicus splits to envelop the rectus abdominis, then reforms in the midline to join and interweave with the fibers of the linea alba. Below the level of the umbilicus (see Fig. 3B), the aponeurosis does not split but rather runs anterior to the rectus muscle, continues medially as a single sheet, joins the anterior rectus sheath, and contributes to the linea alba. The aponeurotic portion of the internal oblique is widest at the level of the umbilicus. The transversus abdominis muscle arises from the fascia along the iliac crest and inguinal ligament and from the lower 6 costal cartilages and ribs, where it interdigitates with the lateral diaphragmatic fibers. The muscle bundles of the transversus abdominis for the most part run horizontally. However, the lower medial fibers may continue in a more inferomedial course toward the site of insertion on the crest and pecten of the pubis. The aponeurosis of the transversus abdominis joins the posterior lamina of the internal abdominal oblique, forming above the umbilicus a portion of the posterior rectus sheath. Below the umbilicus, the transversus abdominis aponeurosis is a component of the anterior rectus sheath. The gradual termination of aponeurotic tissue on the posterior aspect of the rectus abdominis forms the arcuate line of Douglas.
Fig. 2 Abdominal wall musculature (A) Superficial layers (B) Deep layers.
Fig. 3 Composition of rectus sheath above (A) and below (B) the umbilicus. The rectus abdominis forms the central and anchoring muscle mass of the anterior abdomen. The rectus muscle arises from the fifth to the seventh costal cartilages and inserts on to the pubic symphysis and pubic crest. Each rectus muscle is segmented by tendinous intersections at the levels of the xiphoid process and the umbilicus and at a point midway between these 2. The lateral edge of the muscle is demarcated by a slight depression in the aponeurotic fibers, corresponding to the lateral edge of the rectus muscle; this depression is the semilunar line. It marks the site of initial lateral insertion of the aponeurotic tendons of the lateral abdominal muscles. The composition of the rectus sheath varies depending on axial level of the abdominal wall [5]. The anterior sheath superior to the umbilicus is composed of the aponeurosis of the external abdominal oblique and the anterior lamina of the internal abdominal oblique. The transversalis aponeurosis does not participate in the formation of the anterior sheath at this level. The posterior sheath of the rectus muscle superior to the umbilicus is contributed to by the internal abdominal oblique and the transversus abdominis aponeurosis. The external abdominal oblique does not participate in the formation of the posterior portion of the rectus sheath. At a highly variable site inferior to the umbilicus, all the aponeurotic tendons pass anteriorly to form the anterior rectus sheath. The fibers of the posterior sheath are seen to attenuate gradually. This transfer of connective tissue away from the posterior rectus sheath causes the arcuate line of Douglas to form on the posterior surface of the muscle. The tissue covering the deep surface of the rectus muscle inferior to the arcuate line is primarily the transversalis fascia [6]. This anatomic layer is most significant to the surgeon performing a retrorectus hernia repair. The innervation of the anterior abdominal wall muscles is multiple. The lower intercostal and upper lumbar nerves (T7–T12, L1, L2) contribute most of the innervation to the lateral muscles and the rectus abdominis. The nerves pass anteriorly in a plane between the internal oblique and the transversus abdominis, eventually piercing the lateral aspect of the rectus sheath to innervate the muscle. The external oblique muscle receives branches of the intercostal nerves, which penetrate the...